N6VB was being towed along a runway that had been withdrawn from service at Dublin Airport (EIDW) when it collided with a parked aircraft, N20EG.This caused significant structural damage to the nose of N20EG and to a crew van parked alongside.The wingtip of N6VB was also damaged.The Driver of the tug had not maintained adequate separation from the parked aircraft.There was no wing marker in position as required by aerodrome procedures in force at the time and the markings on the taxiway did not conform to the published Aerodrome Directive.There was no fire or injury.